package com.ruoyi.common.utils.wxlogin;
import org.apache.commons.codec.binary.Base64;
import org.bouncycastle.jce.provider.BouncyCastleProvider;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.io.UnsupportedEncodingException;
import java.security.*;
import java.security.spec.InvalidParameterSpecException;

public class AesCbcUtil {
	  // 固定编码
    private static final String encodingFormat = "UTF-8";
 
    /**
     * 对外提供服务
     * @return
     */
    public static String decodeUserInfo(String data, String key, String iv){
        return decodeBase64(data, key, iv);
    }

    /**
     * AES解密
     *
     * @param data           //密文，被加密的数据
     * @param key            //秘钥
     * @param iv             //偏移量
     * @param encodingFormat //解密后的结果需要进行的编码
     * @return
     * @throws Exception
     */
    public static String decrypt(String data, String key, String iv, String encodingFormat) throws Exception {
//        initialize();

        //被加密的数据
        byte[] dataByte = Base64.decodeBase64(data.getBytes());
        //加密秘钥
        byte[] keyByte = Base64.decodeBase64(key.getBytes());
        //偏移量
        byte[] ivByte = Base64.decodeBase64(iv.getBytes());


        try {
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");

            SecretKeySpec spec = new SecretKeySpec(keyByte, "AES");

            AlgorithmParameters parameters = AlgorithmParameters.getInstance("AES");
            parameters.init(new IvParameterSpec(ivByte));

            cipher.init(Cipher.DECRYPT_MODE, spec, parameters);// 初始化

            byte[] resultByte = cipher.doFinal(dataByte);
            if (null != resultByte && resultByte.length > 0) {
                String result = new String(resultByte, encodingFormat);
                return result;
            }
            return null;
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
        } catch (InvalidParameterSpecException e) {
            e.printStackTrace();
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        } catch (InvalidAlgorithmParameterException e) {
            e.printStackTrace();
        } catch (IllegalBlockSizeException e) {
            e.printStackTrace();
        } catch (BadPaddingException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }

        return null;
    }

    /**
     * AES解密
     *
     * @param data // 密文，被加密的数据
     * @param key  // 秘钥
     * @param iv   // 偏移量
     *             //     * @param encodingFormat 	// 解密后的结果需要进行的编码
     * @return
     */
    private static String decodeBase64(String data, String key, String iv) {
        // 被加密的数据
        byte[] dataByte = Base64.decodeBase64(data);
        // 加密秘钥
        byte[] keyByte = Base64.decodeBase64(key);
        // 偏移量
        byte[] ivByte = Base64.decodeBase64(iv);
 
        // BouncyCastle是一个开源的加解密解决方案
        Security.addProvider(new BouncyCastleProvider());
 
        try {
//            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
//            Cipher cipher = Cipher.getInstance("BC");
            Cipher cipher = Cipher.getInstance("AES/CBC/NOPadding");
 
            SecretKeySpec spec = new SecretKeySpec(keyByte, "AES");
 
            AlgorithmParameters parameters = AlgorithmParameters.getInstance("AES");
            parameters.init(new IvParameterSpec(ivByte));
 
            cipher.init(Cipher.DECRYPT_MODE, spec, parameters);// 初始化
 
            byte[] resultByte = cipher.doFinal(dataByte);
            if (null != resultByte && resultByte.length > 0) {
                String result = new String(resultByte, encodingFormat);
                return result;
            }
            return null;
        } catch (Exception e) {
         }
        return null;
    }

}
